But it’s thought Ms Lynch’s decision was also motivated by a desire to focus on her constituency work after a difficult year for the MP.

The Halifax MP has spent the last three months covering the Batley and Spen constituency following the death in June of her friend Jo Cox.

During her year in the whips’ office Ms Lynch has also had to work through the death of Labour colleague Harry Harpham who was MP for Sheffield Brightside and Hillsborough.

Ms Lynch’s victory in Halifax was one of the few highlights for Labour at the 2015 General Election.

Despite being selected as the Labour candidate relatively late and facing a strong Conservative challenge she held onto the marginal seat.

However, Ms Lynch only won with a majority of 428 and boundary changes to the Halifax constituency due to take effect before the next election are expected to benefit the Conservatives. Conor McGinn, MP for St Helens North, has also stepped down from thje whips office.

A Labour spokesman said: “We thank Conor McGinn and Holly Lynch for their services. Their positions will be filled in due course.”

A Labour source said: “No-one will lose any sleep over Conor McGinn resigning after the disloyalty he showed in organising resignations during the attempted coup.”

Sources close to Mr Corbyn insist that Mr McGinn was set to be sacked when junior posts in the reshuffle were announced.

The resignations come in the wake of controversial choice for shadow attorney general, Shami Chakrabarti, comparing the Labour Party to a “war zone”. And the walkouts follow reports that anti-Corbyn figures are preparing to organise their own “shadow shadow cabinet” in competition with the official front bench.